Friction part and method of treating



Patented Sept. 29, 1942 UNITED STATES PATENT OFFICE FRICTION PART AND METHOD OF TREATING Cecil W. Glasaon, Detroit, Mich, asaignor to Parker Bust Proof Company, Detroit, Mich.

No Drawing. Application May 9, 1940, Serial No. 334,239

7 Claims. (Cl. 148-85) king pins, spring leaves, bushings and thrust washers and other parts having sliding surfaces, such as cams of machines, journals, shafts, bearings and the like. This is a continuation in part of Serial No. 220,131, filed July 19, 1938.

In the metal art the points of contact between metallic surfaces and other surfaces where there is movement, furnishes a problem of lubrication to avoid welding, scoring, etc. Oil, of course, solves the problem to a great extent. Graphite also has been employed, usually in connection with oil.

I have found that problems of lubrication in the use of such parts are solved by subjecting the parts to treatment with a solution containing the P04 radical and a metal such as cobalt and nickel. For example, the surfaces of the parts may be treated with a solution containing the dihydrogen phosphates of certain metals or more than one of the metals may be present in the solution. For example, the parts may be processed with a solution of zinc dihydrogen phosphate to which has been added a soluble salt, say, of nickel or cobalt, or a solution of nickel or cobalt dihydrogen phosphate may be used. When dihydrogen phosphates of metals above iron in the electromotive series are employed it is sometimes advantageous to include in the solution a salt of a metal such as nickel or cobalt to obtain smaller crystal size in the phosphate coating.

After the phosphate coat is obtained, oil or graphite may be applied to enhance the lubricating value of the coating. The graphite will ordinarily be applied in the form of colloidal graphite and will usually be used with oil. The graphite oil mixture may be applied as follows:

Immerse the phosphated coated article in a solution containing the following:

One part of a colloidal graphite solution, preferably Oildag", to twenty-five parts of soluble oil by weight, using preferably Superla" (trademark) soluble oil. Heat the soluble oil and graphite to approximately 140 F., so that the two will become more thoroughly mixed. This base mixture of soluble oil and Oildag is then reduced one part to twenty-five parts by volume with water and heated to 140 It, (the ratio of oil residue on a processed part is varied by increasing or decreasing this mixture of oil and water).

Dry the finished surface by blowing air there- It has been found that if the oil and graphite are applied in the above manner that the phosphate coating absorbs the oil and not the water.

A solution for obtaining the phosphate coating that has proved satisfactory in many cases is set forth below:

Pounds Zinc dihydrogen phosphate 900 Zin nxide 250 Nitric acid 42 B 750 Sodium nitrate 600 Water to make 5000 I become depleted it is necessary to add sufficient ingredients to make up for lost strength. Other dihydrogen phosphates may be substituted for the zinc dihydrogen phosphate set forth above, for example, cadmium, calcium, strontium, barium, chromium.

In the example given, and when other phosphates are substituted for the zinc phosphate of the example, it is not always necessary to use the other ingredients in the solution but it is desirable to employ a metal such as nickel or cobalt for reasons already given.

Variations in the conditions, surfaces treated, methods of application, etc., will occur to those versed in the art which, however, will lie within the spirit of this invention, the scope of which is to be measured only by the following claims.

What I claim is:

1. An article of manufacture having a ferrous bearing surface normally lubricated and employed in moving contact with another surface, said ferrous surface having thereon a chemically produced, lubricant-retaining phosphate coating comprising metal of the group consisting of cobalt and nickel.

2. An article of manufacture having a ferrous bearing surface normally lubricated and employed in moving contact with another surface, said ferrous surface having thereon a chemically produced phosphate coating comprising metal of the group consisting of nickel and cobalt, and graphite and oil held in place on the surface by the phosphate coating.

3. An article of manufacture having a ferrous bearing surface normally lubricated and employed in moving contact with another surface, said ferrous surface having thereon a chemically produced, lubricant-retaining phosphate coating comprising zinc phosphate and nickel.

4. The process of preparing a ferrous surface for use as a lubricated bearing surface, which comprises treating the surface with a phosphate ing solution containing nickel until a phosphate coating is produced on said surface, and then impregnating the phosphate coating with a lubricant.

6. The process of preparing a ferrous surface for use as a lubricated bearing surface, which comprises treating the surface with a phosphate coating solution containing nickel until a phosphate coating is produced on said surface, and then applying to the phosphate coating a solution of water, water soluble oil and graphite, and drying the surface.

7. The process of preparing a ferrous surface for use as a lubricated bearing surface, which comprises treating the surface with a phosphate coating solution containing nitrate and nickel until a phosphate coating is produced on said surface, and then impregnating the phosphate coating with'a lubricant.

I CECIL W. GLASSON. 

